Tensioning method and device of two-for-one yarn twisters



May 27, 1969 TEU, NAKAHARA ET AL 3,445,998`

TENSIONING METHOD AND DEVICE OF TWO-FORONE YARN TWISTERS Filed June 14. 1967 Sheet WED' May 27, 1969 TEIJI NAKAHARA ET A1. 3,445,998

TENSIONING METHOD AND DEVICE OF TWO-FOR-O NE YARN TWISTERS Filed June 14, 1967 sheet of2 3,445,998 TENSIONING METHOD AND DEVICE F TWO-FOR-ONE YARN TWISTERS 'Ieiji Nakahara, Mitsuo Fukunaga, and Toshyuki Yamashita, Kyoto-shi, Japan, assignors to Murata Machinery, Ltd., Kyoto-shi, Japan, a company of Japan Filed .lune 14, 1967, Ser. No. 645,987 Claims priority, application Japan, Sept. 2, 1966, 41/ 58,107 Int. Cl. Dtllh 1/10, 7/86; B6Sh 59/04 U.S. Cl. 57-58.84 13 Claims ABSTRACT 0F TI-IE DISCLOSURE A method and device for controlling unravelling tension of a yarn from a package on a two-for-one yarn twister. The package is mounted on a rotatable package receiver and starts to rotate when excessive unravelling tension is loaded upon the unravelling yarn. On an advansing path, the yarn is positively wound around a spindle within a lower tension device at a given winding angle. Excessive yarn tension is prevented `by the rotation of the package while small fluctuation of the yarn tension is compensated by the winding path .of the yarn.

The present invention relates to an improved tensioning method and device of `a two-for-one yarn twister, more particularly relates to .an improved method and device of a two-for-one yarn twister for controlling the yarn tension so that it is uniform throughout the twisting operation.

It is well-known that yarns processed on a two-for-one yarn twister especially at a high speed are exposed to a variety of excessive tension loads. In case of many yarns, both yarns spun from staple fibers and synthetic rilament yarns, such excessive tension lo-ads are undesirable because :the yarns undergo a severe .strain and frictional contact, especially in case of synthetic filament yarns, and, as a result, they will be overstretched, damaged or broken.

Many attempts have been rnade to control yarn tension so that it is uniform throughout the twisting operation. A typical example of the above-mentioned attempts is disclosed in U.S. Patent No. 3,293,839 in which a control means comprising a ball, a washer and a gate tension mechanism is applied, while other typical examples of the attempts .are disclosed in U.S. Patent No. 2,958,995 and U.S. Patent No. 3,001,356, in which means for winding a yarn around a yarn storage disks is provided for the purpose. In case of the former example, it -is possible to control `a small variation of yarn tension uniformly, but it is not suitable for a large lfluctuation in yarn tension, .while in case of the later example, frictional contact of passing yarn with the yarn storage disk often results in undesirable damages of the yarn.

A principal object of the present invention is `to provide an improved method and `device of a two-for-one yarn twister for preventing the yarn from receiving excessive tension even when the twister is driven at a high speed.

Another object of the present invention is to provide an improved method and device of a two-for-one yarn twister for controlling the yarn tension so that it is uniform throughout the twisting opera-tion.

A 'further object of the present invention is lto provide an improved method .and device of -a two-for-one yarn twister for applying a minimum but necessary tension to the yarn throughout :the twisting .opera-tion.

A still further object of the present invention is to provide -an improved method yand device of `a two-for-one nited States Patent C) 3,445,998 Patented May 27, 1969 yarn twister for obtaining a yarn of better quality at 4a lower operation oost..

`In the conventional method of yarn-twisting on a twofor-one yarn twister, the yarn is drawn olf from a yarn package mounted on a non-moving tension disk and is conducted through `a tension device installed in the upper end of bobbins (hereafter called the upper tension device) to a longitudinal bore in the spindle, then to a tension accumulator disk installed in the lower end of bobbins (hereafter called the lower Itension device), and finally to a preliminary draw-olf device positioned above the twister in a ballooned condition.

In case ofthe method and device ofthe present invention, according to lthe .above-described objects of the invention, a yarn drawn out of a package is advanced in an -almost similar manner to the conventional two-forone yarn twister. However, 'the method and device of the present invention is remarkably different from the conventional ones in that loading of excessive tension upon the un-ravelling yarn is effectively prevented by the fact that; primary, the package starts to rot-ate when excessive unravelling tension is loaded upon the unravelling yarn and; secondary, the yarn is advanced winding itself around the spindle within a lower tension device at a given winding angle. Therefore, increase of the unravelling tension caused by the decrease in package diameter is prevented by the rotation of the package while small fluctuation of the unravelling tension of the yarn is compensated by the winding of the yarn around the spindle within the low tension device. For this purpose, the twofor-one yarn twister of the present invention comprises, in combination, a spindle, a lower tension device secured to the spindle, a rotatable package receiver for mounting the package thereon, a package holder rotatably disposed to the spindle and a known type of upper tension device secured to the top of the package holder. Arrangement of the lower tension device is designed in such a manner that it causes the above-described winding path of the yarn at a given winding angle around the spindle within the lower tension device.

The present invention will be better understood from the following description taken in connection with the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

FIG. 1 is a vertical sectional view of a two-for-one yarn twister embodying the present invention,

FIG. 2 is a perspective elevational View of a lower tension device of the present invention,

FIG. 3 is a plan sectional view taken along the line III-III in FIG. 2,

FIG. 4 is a perspective view of a yarn guide piece used for the lower tension device embodying the present invention,

FIG. 5 is a perspective view of another yarn guide piece used for the lower tension device embodying the present invention,

FIG. 6 is a plan sectional View taken along the line III-III in FIG. 2 when the yarn guide piece shown in FIG. 5 is applied instead of the yarn guide piece shown in FIG. 4,

FIGS. 7 and 8 are schematic explanatory drawings showing a passage of the yarn in the lower tension device.

The structure of the apparatus of the present invention is shown in FIG. l. In the two-for-one yarn twister of the present invention, a known type of conventional tensioning device is installed compactly Within a tension device main structure 1 forming a longitudinal yarn passage 2. The tension device main structure 1 is tted to an upper supporting member 3 which is supported by a cylindrical package holder 4 in such a manner that the upper supporting member 3 can be Adisengaged from the upper end portion of the cylindrical package holder 4. A pair of iiyers 5, 5 are engaged rotatably with the upper supporting member 3 by means of a bearing 6 so as to encourage the unravelling of a yarn 7 from a yarn package 8 during the unravelling operation. The lower end portion of the cylindrical package holder 4 is fitted fixedly to a bush 9 and the lower portion of the bush 9 is thrust into the central portion of a non-moving tension disk 10, while a bearing 11 is fitted to the upper portion of the bush 9. A yarn bobbin 12 is mounted on a package receiver 13 disposed to the bearing 11 in such a manner that the yarn bobbin 12 can be rotated freely together with the package receiver 13 when the revolving force applied to the yarn package 8 exceeds the frictional resistance of the bearing 11. A spindle 14 is rotatably mounted within the non-moving tension disk through a pair of bearings 15, 15 in a coaxial condition. The non-moving tension disk 10 is prevented from rotation by an attracting force produced between a plurality of inner magnets 16, which are disposed to edges of the non-moving tension disk 10 between an upper flange 17 and a lower ange 18 thereof, and a plurality of outer magnets 19 arranged outside of the disk 10 in a face to face condition with respective inner magnets 16. A balloon-limiting mantle 20 is secured to the upper flange 17 of the non-moving tension disk 10 by a screw 21 so as Vto control the ballooning of the yarn 7 unravelling from the yarn package 8. A yarn storage disk 22, which is fitted to the spindle 14 at the central portion of the storage disk 22 in such a manner that the storage disk 22 rotates with the rotation of spindle 14, is secured to an upper flange 23 of a spindle whorl 24 by a screw 25 and is provided with at least a lower yarn guide 26 which is disposed to the edge portion of the storage disk 22 from its under side. A yarn guide piece 27, which is preferably made of a material of low frictional resistance and is provided with a bore 28 for the passage of the yarn, is inserted into the hole bored horizontally through the neck portion of the spindle whorl 24 and the spindle 14 in such a manner that the horizontal bore 28 of the yarn guide piece 27 meets the longitudinal bore of the spindle 14 so as to conduct the yarn 7 to the yarn guide 26 after the yarn 7 has passed through the longitudinal bores of the cylindrical package holder 4 and the spindle 14. A plurality of yarn guide poles 29, which are preferably made of material of low frictional resistance, are arranged around the neck portion of the spindle whorl 24. A mantle disk 31 is disposed to the spindle whorl 24 by some known means so as to avoid diversion of yarn ends around the bottom portion of the twister when the yarn 7 is broken during the take-up operation by storing the broken yarn end in a space between the edge portion of the yarn storage disk 22 and the edge portion of the mantle disk 31. A snail wire 32 is positioned above the twister in order to conduct the yarn 7 from the twister to a draw-off device (not shown) after the completion of the twisting operation.

When the take-up operation starts in the present invention, the yarn 7 is unravelled from the yarn package 8, advanced upwardly to the longitudinal yarn passage 2 of the tension device main structure 1 by the rotating yer 5 and then advanced into the longitudinal bore of the cylindrical package holder 4. Next, after passing through the longitudinal bore of the cylindrical package holder 4, the yarn 7 is advanced further downward through the longitudinal bore of the spindle 14 and into the horizontal bore 28 of the yarn guide piece 27. During this unravelling process, the yarn 7 is given a primary twist under the minimum tension required. After coming out of the bore 28, the yarn 7 winds itself around the neck portion of the spindle whorl 24 in a condition it touches the yarn guide poles 29 at a large or a small looping angle. Then the yarn 7 is advanced outside of the device through the yarn guide 26 of the yarn storage disk 22, and finally to a snail wire 32 positioned above the twister in ballooning condition. The yarn 7 is given a secondary twist during this draw-off process and this is added to the primary twist given during the foregoing unravelling process so as to have a definite amount of twist as the total of the twists given during those two processes.

In the conventional method of two-for-one yarn twister, unravelling of the yarn from the yarn package can be carried out without trouble only when the diameter of the yarn package is large but as the diameter of the yarn package becomes smaller, it becomes relatively difficult to unravel the yarn from the yarn package because the inner portion of the yarn package is often deformed on account of the internal winding pressure and because the yarn tension is increased gradually as the diameter of the yarn package decreases. In order to overcome those diiculties, a yer has been applied to the conventional method which encourages unravelling of the yarn from the yarn package. However, the increased unravelling resistance of the yarn caused by the decreased diameter of the yarn package results in abnormal rotation of the yer and the increased speed of the flyer rotation causes excessive unravelling of the yarn from the yarn package. Consequently, even the application of a flyer cannot eliminate completely the trouble caused when the diameter of the yarn package becomes smaller.

In the method of the present invention, the yarn package 8 is mounted on the package receiver 13 in a stationary condition when the diameter of the yarn package 8 is large and the yarn 7 is unravelled from the yarn package 8 only by means of the rotation of the yer 5, 5. In this stage of yarn unravelling, the frictional resistance of the bearing 11 caused by the weight of the yarn package 8 is larger than the revolving force applied to the yarn package 8 by the unravelling tension of the yarn 7. And, as the unravelling of the yarn 7 progresses, the weight of the yarn package 8 decreases gradually and the frictional resistance of the bearing 11 caused by the decreased weight of the yarn package 8 becomes smaller gradually. When the frictional resistance of the bearing 11 caused by a further decrease in weight of the yarn package 8 becomes smaller than the revolving force applied to the yarn package 8 caused by the increased unravelling tension of the yarn 7, the package 8 begins to rotate gradually around the cylindrical package holder 4 together with the bearing 11 and the package receiver 13. In the unravelling mechanism of the present invention, the yarn is prevented from receiving excessive tension by making the yarn package rotatable when the unravelling tension of the yarn becomes larger than a certain amount. Consequently, the method of the present invention can eliminate yarn breakage which often takes place when the diameter of the yarn package becomes smaller and draw-off of the yarn completely from the yarn package can be carried out without any trouble even when a large amount of yarn is wound on a yarn bobbin of a relatively small diameter.

Referring to FIGS. 2, 3 and 4, detailed structure of the lower tension device of the present invention is shown. The lower tension device comprises a plurality of yarn guide poles 29, which are preferably made of material of low frictional resistance, these are arranged around the neck portion 33 of the spindle whorl 24 between the upper ange 23 and a conically sloping surface 30 of the spindle whorl 24 in such a manner that the upper end portions of the guide poles 29 are secured to the upper flange 23 while the lower end portions of the guide poles 29 are secured to the conically sloping surface 30 of the spindle whorl 24 and a yarn guide piece 27, which is also made of material of low frictional resistance, is inserted into the hole bored horizontally through the neck portion 33 of the spindle whorl 24 and the spindle 14 in such a manner that the horizontal bore 28 of the yarn guide piece 27 meets the longitudinal bore of the spindle 14 at right angle as shown in FIG. 3.

The structure of the yarn guide piece 27 is shown in FIG. 4, wherein the yarn guide piece 27 comprises a anged portion 34 provided with a groove 35 horizontally formed on the sectional surface 36 of the anged portion 34 for smooth passage of the yarn drawn-off, a long body portion 37 extending from another sectional surface of the flanged portion 34 and a downwardly opened horizontal bore 28 bored along the longitudinal axis of the long body portion 37 so as to connect the horizontal bore 28 with the longitudinal bore of the spindle 14.

Referring to FIGS. and 6, another embodiment of the yarn guide piece 27 of the present invention is shown, wherein the yarn guide piece 27 comprises two elements, each of which having a long tbody portion 40; 40", a flanged portion 41, 41', downwardly opened bore 42 bored along the longitudinal axis of each long Ibody portion 40, 40', and a semi-circular bore 44, 44' bored downwardly from the upper surface of the long body portion 40, 40'. Inserting the elements of the guide piece 7 into the hole of the neck portion 33 of the spindle whorl 24 from both sides as shown in FIG. `6, the bore 42 of each element is joined so as to draw off the yarn 7 from any side of the guide piece 27 as required, and the semi circular bore 44 and 44 meets to form a circular bore so as t-o conduct the yarn 7 into the bore 42.

Referring to FIGS. 7 and 8, the yarn 7 is advanced outside of the spindle 14 through the bore 28 of the yarn guide piece 27 and, after winding itself around the neck portion 33` of the spindle whorl 24 at a winding angle of about 90 in case of the embodiment shown in FIG. 7 and at a winding angle of about 270 in case of the embodiment shown in FIG. 8 while contacting the plurality of yarn guide poles 2.9 arranged around the neck portion 33 of the spindle whorl 27, it is further advanced outside of the apparatus through a yarn guide 26 disposed to the edge portion of the yarn storage disk 22 to be drawn off by the snail wire 32 positioned above the twister. The extent of yarn winding angle around the neck portion 33 of the spindle whorl 24 can be adjusted according to the kind of yarn ibeing twisted lby means of the directional relation between the yarn guide piece 27 and the yarn guide 26.

In the conventional method of twisting yarn on a twofor-one twister, the yarn was conducted directly from the bottom exit of the bore of the spindle to the yarn guide disposed to the yarn storage disk so that a large amount of tension required for twisting operation must be applied to the yarn by the upper tension device at one time and this resulted in defective operational conditions Vsuch as filament separation due to electrostatic charges, formation of loops of iilament in the yarn and lament breakage.

However, in the method of the present invention, the tension of the yarn required for the twisting operation is applied in two steps. a minmum tenis applied to the by the upper tension `device and, in the second step, a suitable tension necessary for giving the secondary twist is applied to the drawn-olf yarn by winding the yarn around the neck portion of the spindle whorl in a condition it contacts the yarn guide poles at a suitable angle. Consequently, the yarn can be twisted on the apparatus of the present invention without receiving excessive tension during the twisting operation.

While the invention has been described in conjunction with certain embodiments thereof it is to be understood that various modifications and out departing from the spirit and scope of the invention.

What is claimed is:

1. A process for unwinding yarn from a spindle mounted package comprising drawing said yarn olf said package whereby as the diameter of the remaining yarn decreases tension increases; tensioning said yarn once; winding said yarn about said spindle at a fixed wrap angle to achieve a second tensioning whereby small tension fluctuations are absorbed; rotating said package when said tension increases above a predetermined amount; whereby the increased tension is reduced by the rotation of said package.

2. A process of unwinding yarn from a package rotatably supported on a hollow spindle comprising drawing said yarn off said package whereby as the diameter of the package decreases the tension increases, passing said yarn through a rst tension device located above the package, passing said yarn down through said spindle to a second tension device, positively winding said yarn around said spindle within said second tensioning device at a selected constant wrap angle, drawing said yarn from said second tensioning device and rotating said package in a direction to reduce tension of the yarn when said tension increases above a predetermined amount.

3. A process as in claim 1 wherein said wrap angle is between and 270.

4. An apparatus for unwinding yarn from a package comprising a hollow spindle receiving said package means for drawing said yarn off said package whereby as the diameter of the package decreases the tension increases; first and second tension devices located above and below the package respectively; means for passing said yarn through said tirst tensioning device to said second tensioning device; means for positively winding said yarn around said spindle at a selected constant wrap angle, means for guiding said yarn from said winding means; and means for rotation of said package in a direction to reduce tension of the yarn when said tension increases above a predetermined amount.

I5. An apparatus as in claim 4 wherein said wrap angle is between 90 and 270.

y6. An apparatus as in claim means comprisings a hollow shaft and in alignment therewith.

7. An apparatus as in claim 4 wherein said drawing means comprises an arm, having a hole, rotatably mounted on said passing means.

8. An apparatus as in claim 4 wherein said first tensioning device comprises a hollow cone mounted on said passing means.

9. An apparatus as in claim 4 wherein said second tensioning device comprises a tube having a bore communicating at a right angle with said hollow spindle.

10. An apparatus as in claim v5 wherein said winding means comprises a plurality of parallel poles disposed circumferentially around said spindle.

11. An apparatus as in claim 6 wherein said guiding means comprises a storage disk, having a hole, mounted on said spindle.

12. An apparatus as in claim 7 wherein said means for rotation comprises a stationary disk having a ball bearing assembly with said package mounted thereon.

13. An apparatus for unwinding tensioned yarn from a package comprlsing a stationary tension disk; a hollow 4 wherein said passing mounted on said spindle to receive said yarn; device mounted on top of said holder having a bore communicating with said holder bore for receiving said yarn; an arm, having a hole, rotatably mounted on said holder; a storage disk, having a hole mounted on said spindle to rotate therewith; a plurality of parallel poles circumferentially mounted around said spindle; a tube havin-g a bore communicating with said hollow shaft; a second yarn guide mounted in said tension disk hole non-aligned with said tube bore to receive said yarn after a wrap angle of 90 to 270 about said spindle; whereby as said yarn 7 8 cornes oi said package it receives a rst tensioning and FOREIGN PATENTS thereafter a second tensioning due to said wrap angle 1,445,250 5/1966 Frame, and said receiver begins rotating when said yarn tension 961,853 6/ 1964 Great Britain. goes above said predetermined amount to relieve said 304680 1/1955 Switzerlandtension. 5 OTHER REFERENCES References Cited DAS 1,026,206, Germany, Schwarm, 57/58.s6, publ. UNITED STATES PATENTS October 1958. 1,900,037 3/1933 Bochmann et al 57 58 84 DAS 1,141,569, Germany, Volkmann, 57/58.49, publ.

2,534,496 12/1950 Agresti. 10 December 1962' 2,958,995 11/ 1960 Gollos et al 57-58.84 STANLEY N. GIBREATH, Primary Examiner. 3,153,894 10/1964 Kreuschmer 57-5s.s3 XR W, H SCHROEDERs ,4m-mn, Exam-eh 3,298,167 1/1967 Keyser 57 5s.s4

3,316,703 5/1967 McKelvie 57-106 15 U-S- C1XR- 3,362,151 1/1968 Franzen 57-58.84 57-58.86; 242-147 

